The present invention relates generally to gas pressure gauges, and more particularly provides a removable, in-place refrigerant pressure check gauge connectable to the low pressure test and service valve fitting on an automobile air conditioning refrigerant circuit.
It is well known that the refrigerant pressure in automobile air conditioning systems must be periodically checked to assure that the refrigerant circuit is properly charged to provide adequate operation of the air conditioning system. In the past, such periodic checking of the refrigerant pressure has been accomplished by temporarily connecting a suitable gauge device to the low pressure test and service valve fitting in the refrigerant circuit, and then removing and storing the gauge device for later use as necessary. Because of the compactness of the modern car air conditioning system, and the proximity of its various components to various engine parts, this conventional refrigerant pressure testing method is often a somewhat awkward and cumbersome task requiring, in many instances, a considerable degree of manual dexterity in temporarily connecting the pressure check gauge to the refrigerant service valve within the crowded engine compartment.
One type of conventional pressure check gauge has the general appearance of a "pop-out" tire pressure gauge having an elongated body provided at one end with a temporary connection fitting which must be pressed onto and held against the test and service valve fitting, and an elongated indicator rod housed within the body which is forced outwardly through the opposite body end by refrigerant pressure, the extent to which the rod is forced outwardly from the body being indicative of the refrigerant pressure being tested.
Another conventional form of the pressure check device comprises a cylindrical pressure gauge having a flexible pressure inlet hose secured thereto and having a service valve connection fitting at its outer end which is adapted to be forced onto and temporarily held against the test and service valve to generate a pressure reading on the gauge.
These and other similar conventional pressure check devices, in addition to the difficulty often encountered in temporarily connecting them to the test and service valve, are also easily misplaced when remotely stored during the interim between periodic refrigerant pressure checks.
It is accordingly an object of the present invention to provide a refrigerant pressure check device which eliminates or minimizes above-mentioned and other problems and limitations typically associated with conventional refrigerant pressure check devices.